In all cases listed above, including both commercial and non-commercial, “spam happens” due to a positive Cost-benefit analysis result.
Cost is the combination of
- Overhead: The costs and overhead of electronic spamming include bandwidth, developing or acquiring an email/wiki/blog spam tool, taking over or acquiring a host/zombie, etc.
- Transaction cost: The incremental cost of contacting each additional recipient once a method of spamming is constructed, multiplied by the number of recipients. (see CAPTCHA as a method of increasing transaction costs)
- Risks: Chance and severity of legal and/or public reactions, including damages and punitive damages
- Damage: Impact on the community and/or communication channels being spammed (see Newsgroup spam)
Benefit is the total expected profit from spam, which may include any combination of the commercial and non-commercial reasons listed above. It is normally linear, based on the incremental benefit of reaching each additional spam recipient, combined with the conversion rate.
Spam is prevalent on the Internet because the transaction cost of electronic communications is radically less than any alternate form of communication, far outweighing the current potential losses, as seen by the amount of spam currently in existence. Spam continues to spread to new forms of electronic communication as the gain (number of potential recipients) increases to levels where the cost/benefit becomes positive. Spam has most recently evolved to include wikispam and blogspam as the levels of readership increase to levels where the overhead is no longer the dominating factor. According to the above analysis, spam levels will continue to increase until the cost/benefit analysis is balanced .
Source : wikipedia